The Stable or Metastable Phases in Compressed Zn-O Systems

Variable-composition evolutionary structure searches are used to explore stable stoichiometries for the Zn-O system below 300 GPa. Our results confirm the previous structural phase transition sequence of pressurised ZnO. ZnO is thermodynamically stable up to 300GPa and zinc peroxide （Zn02, space group Pa3） is metastable under lower pressure. Insulating I4/mcm-Zn02 is thermodynamically stable between 128.3-300 GPa. Insulated metastable P3121-Zn02, controlling the pressure range of 51.5-128.3 GPa, has a wide band gap compared to the Pa3-Zn02 and I4/mem-Zn02. Phonon and elastic constant calculations conclude the dynamical and mechanical stability for the explored thermodynamically stable or metastable structures.

Structure and properties of FeCoNiCrCu_(0.5)Al_x high-entropy alloy

Effects of Al content and heat treatment on the structure,hardness and electrochemical properties of FeCoNiCrCu0.5Alx high-entropy alloys were investigated.The phase structure of as-cast alloys evolves from FCC phase to BCC phase with the increase of Al content.The stable phase of FeCoNiCrCu0.5Alx high-entropy alloys will transform from FCC phase to FCC＋BCC duplex phases when x value increases from 0.5 to 1.5.The hardness of BCC phase is higher than that of FCC phase,and the corrosion resistance of BCC phase is better than FCC phase in chlorine ion and acid medium.High hardness and good corrosion resistance can be obtained in as-cast FeCoNiCrCu0.5Al1.0 alloy.

Theoritical and Experimental Studies on the Phase Equilibria and Phase Diagrams on the Salt-Water Systems

1 Introduction Salt lakes are widely distributed in the world,and salt lakes in China are mainly located in the area of the Qinghai-Xizang(Tibet),and the Autonomous Regions of Xinjiang and Inner Mongolia.There are more than 700salt lakes,each with an area larger than 1 km2,in the

Detecting stable phase structures in EEG signals to classify brain activity amplitude patterns

Obtaining an electrocorticograms(ECoG)signal requires an invasive procedure in which brain activity is recorded from the cortical surface.In contrast,obtaining electroencephalograms(EEG)recordings requires the non-invasive procedure of recording the brain activity from the scalp surface,which allows EEG recordings to be performed more easily on healthy humans.In this work,a technique previously used to study spatial-temporal patterns of brain activity on animal ECoG was adapted for use on EEG.The main issues are centered on solving the problems introduced by the increment on the interelectrode distance and the procedure to detect stable frames.The results showed that spatial patterns of beta and gamma activity can also be extracted from the EEG signal by using stable frames as time markers for feature extraction.This adapted technique makes it possible to take advantage of the cognitive and phenomenological awareness of a normal healthy subject.

Generating monoenergetic proton beam by using circularly polarized laser

The interaction of ultrashort intense circularly polarized laser with ultra thin overdense foil is studied by particle-in-cell simulation and analytic model. It is found that with the balance between pondermotive force and electrostatic force, highly quasi-monoenergetic proton beam can be generated by Phase Stable Acceleration (PSA) process. As in conventional accelerators, ion will be accelerated and bunched up in the longitudinal direction at the same time.